Kinematic Characteristics of Snatch Techniques in an Elite World-Record Holder of Weightlifting: A Case Study

Aim: This study aimed to analyze the kinematic characteristics of snatch techniques in a world-class weightlifter who holds the world record in the 73 kg category. Methods: Two high-speed cameras (Sony, Tokyo, Japan, 25 Hz) were used to collect kinematic data at the 2019 Weightlifting World Championships. The SIMI° motion capture system (Simi Reality Motion Systems GmbH, Munich, Germany, 50 Hz) was used to analyze the snatch performance. Results: The lower limb movement during the first pulling stage showed a similar trajectory to elite weightlifters. The athlete showed 5.62° of knee flexion along with continuously increasing barbell velocity (maximal velocity up to 1.90 m/s) in the second pulling. Considering the perimeters of technical stability, the maximal value of the distance between the center of gravity of the human body and that of the barbell was 17.20 cm after the second pull. In addition, the barbell center simultaneously shifted 7.00 cm to the right. Conclusions: These results suggest that the world-record weightlifter possesses special technical characteristics. This personalized technical model provides basic information for the training of other elite weightlifters

Exploring beam size measurement based on the Talbot effect at BEPCII

Vertical beam size measurements were carried out at Beijing Electron–Positron Collider II (BEPCII) using a phase grating and an absorption grating based on the Talbot effect. The transverse coherence of synchrotron radiation is closely related to beam size. Due to the partial coherence of the synchrotron radiation source, the coherence length can be calculated by measuring the visibility decay of interferograms recorded at different distances behind the gratings. A vertical beam size of 68.19 ± 2 µm was obtained based on the relationship between the coherence length and beam size at the 3W1 beamline of BEPCII. A comparison of the vertical emittance derived from the grating Talbot method and the synchrotron radiation visible light interferometer method was presented. The vertical emittances from the two methods are 1.41 nm rad and 1.40 nm rad, respectively. The 0.1% difference indicates that the grating Talbot method for beam size measurement is reliable. This technique has great potential for small beam size measurement of fourth-generation synchrotron radiation light sources, considering its small diffraction limitation and simple experimental setups

Optical Encryption Based on Computer Generated Holograms in Photopolymer

An optical encryption method based on computer generated holograms printing of photopolymer is presented. Fraunhofer diffraction is performed based on the Gerchberg-Saxton algorithm, and a hologram of the Advanced Encryption Standard encrypted Quick Response code is generated to record the ciphertext. The holograms of the key and the three-dimensional image are generated by the angular spectrum diffraction algorithm. The experimental results show that large-size encrypted Quick Response (QR) code and miniature keys can be printed in photopolymers, which has good application prospects in optical encryption. This method has the advantages of high-density storage, high speed, large fault tolerance, and anti-peeping

ELMO1 Deficiency Reduces Neutrophil Chemotaxis in Murine Peritonitis

Peritoneal inflammation remains a major cause of treatment failure in patients with kidney failure who receive peritoneal dialysis. Peritoneal inflammation is characterized by an increase in neutrophil infiltration. However, the molecular mechanisms that control neutrophil recruitment in peritonitis are not fully understood. ELMO and DOCK proteins form complexes which function as guanine nucleotide exchange factors to activate the small GTPase Rac to regulate F-actin dynamics during chemotaxis. In the current study, we found that deletion of the Elmo1 gene causes defects in chemotaxis and the adhesion of neutrophils. ELMO1 plays a role in the fMLP-induced activation of Rac1 in parallel with the PI3K and mTORC2 signaling pathways. Importantly, we also reveal that peritoneal inflammation is alleviated in Elmo1 knockout mice in the mouse model of thioglycollate-induced peritonitis. Our results suggest that ELMO1 functions as an evolutionarily conserved regulator for the activation of Rac to control the chemotaxis of neutrophils both in vitro and in vivo. Our results suggest that the targeted inhibition of ELMO1 may pave the way for the design of novel anti-inflammatory therapies for peritonitis

The effect of laser acupuncture on hypoxia tolerance and inflammation reaction in mice with optical fiber acupuncture needle intra body

Hypoxia is a disorder in which the tissues are not oxygenated adequately. The lack of oxygen may cause irreversible damage to the major organs such as the brain, heart and lungs. In severe cases, coma, seizures, and death may happen. In addition to the routine medication, acupuncture treatment has been applied as a complementary treatment to counter hypoxia. In this paper, the optical fiber acupuncture needle was fabricated using the optical fiber imbedding into the metal capillary tube with needle tip, therefore made it easy to insert into the body for the laser treatment. The laser optical fiber needle treatment to the ST36 acupoint conducted with the laser irradiation intra body. The normobaric hypoxia tolerance test results in mice show that the optical fiber needle treatment to the ST36 acupoint with laser acupuncture appears to improve the tolerance to hypoxia. The mice treated with laser acupuncture expressed high level of IL-1β in serum. Our results suggest that laser optical fiber needle acupuncture may serve as a potential treatment for hypoxia

High Efficiency CdS/CdSe Quantum Dot Sensitized Solar Cells with Two ZnSe Layers

CdS/CdSe quantum dot sensitized solar cells (QDSCs) have been intensively investigated; however, most of the reported power conversion efficiency (PCE) is still lower than 7% due to serious charge recombination and a low loading amount of QDs. Therefore, suppressing charge recombination and enhancing light absorption are required to improve the performance of QDSCs. The present study demonstrated successful design and fabrication of QDSCs with a high efficiency of 7.24% based on CdS/CdSe QDs with two ZnSe layers inserted at the interfaces between QDs and TiO₂ and electrolyte. The effects of two ZnSe layers on the performance of the QDSCs were systematically investigated. The results indicated that the inner ZnSe buffer layer located between QDs and TiO₂ serves as a seed layer to enhance the subsequent deposition of CdS/CdSe QDs, which leads to higher loading amount and covering ratio of QDs on the TiO₂ photoanode. The outer ZnSe layer located between QDs and electrolyte behaves as an effective passivation layer, which not only reduces the surface charge recombination, but also enhances the light harvesting